In another four boroughs, four companies were awarded 80 to 99 per cent of the waste collection contracts:

Camille Fontaine et Fils inc.

Enlèvement de déchets Bergeron inc.

JR Services Sanitaires

RCM Environnement inc./RCI Environnement inc.

"Our auditing has revealed sufficient evidence to enable us to seriously suspect that this practice [of collusion] is likely, which is not conducive to getting the best price for the services requested," the report said.

Bergeron found similar results in the awarding of snow-clearing and snow removal contracts.

In nine boroughs, the same ten companies were awarded snow removal contracts from 2005 to 2013.

When it came to transporting snow, the same five companies obtained city contracts in those nine years.

In his report, Bergeron said four companies — Gaston Contant inc., Construction DJL inc., Environnement Routier NRJ inc., Construction J. Richard Gauthier inc. — got $20.4 million, or 88 per cent, of the total contracts awarded in that time frame.

From 2005 to 2013, the City of Montreal spent more than $490 million for snow removal operations and about $295 million for garbage and recycling collection.

Recommendations

The auditor general recommended that the authorities intervene "as soon as possible to stop certain collusive practices that seem to exist in sectors other than those related to the field of the construction of infrastructure."

He also proposed to establish common monitoring mechanisms between Montreal and its boroughs to be able to compare costs between different districts and be able to note if there are significant price differences.

Mayor calls for investigation

Montreal Mayor Denis Coderre says the city's inspector general will get involved.

Montreal Mayor Denis Coderre said the city's inspector general will investigate. (CBC)

"If it is criminal, it will send it to UPAC (the province's anti-corruption unit). If there are things we can do on the administrative level, we will take the recommendations and will implement them immediately. We have the leftovers of the past administrations," Coderre said late Monday afternoon.

He also said there will soon be an administrative reorganization so that all the borough leaders can communicate with each other.

"I created a table of mayors so that everyone can talk. We must have better coordination," Coderre said.

Opposition leader Richard Bergeron said it's time to finish cleaning up the city's public contracts.

"I hope in the next 12 to 24 months, we will have the same clean-up that we successfully did in the public works sector," Bergeron said.